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Re: Seebeck/peltier...

""I am not going to put up with this crap, anymore.""JC

What crap? you have avoided a technical discussion of any kind..

""Jneutron, if you have ANY possible evidence that the 'Seebeck Effect' could have ANYTHING to do with my measurements, then bring it out! This is a DC effect of thermoelectric power generation. How could it be otherwise?""JC

Where to start??

Ok, get a peltier module..buy it somewhere.. Notice that it is capable of two way heat transfer..It's commercial stuff, everyone can get it..

It is possible to drive one with a bipolar current source..The current direction will determine the heat flow path..I was considering it for my heat controlled plate for my IA circuitry. By monitoring the setpoint vs actual, the bipolar drive can either cool or heat the plate..

The problem with that is the time constant of the assembly. It is very slow, and makes the circuit "breath", so to speak. And it causes horizontal gradients on the plate, and that is the thing I'm trying to avoid the most.

So, I am simply going to use some surface mount resistors to heat, put the assembly ten degreec C over room, then provide a controlled heat leak to the outside world.

Now as to our discussion??? Take the module, and apply a .01 hz signal to it.. Note the temperatures on each surface will track the current. Also note the I/V response of the device itself. It is not a pure resistor, it's non linear, and the hysteresis it shows is not unlike that of iron's, although a different storage and loss mechanism is at work..
Now, increase the drive frequency..You will notice that it's response will begin to roll off, that occuring when the speed of heat transport in conjunction with the the heat capacity (that relation is called diffusivity) prevents the thermal fronts from reaching the surfaces. There is still heat transport ocurring..it's just that the speed at which the heat flow occurs starts to become slow compared to the drive signal.

But, if you look at the I/V characteristics even at high frequency, it is still there, and still non linear.

To make the device act at higher frequencies, it is necessary to either speed up the heat transport (cooling to cryogenic temperatures does that by decreasing the heat capacity of the materials w/r to thermal conductivity...copper heat capacity drops 3 orders of magnitude at 4K while retaining thermal conductivity), or decrease the physical dimensions of the device. Unfortunately, by doing that, the device efficiency decreases due to thermal conductivity of the device.

Now...All dissimilar metal interfaces show the effect to varying degrees. (( I believe the King of Sweden had a face to face with the person who showed that)). So, why would you make the assumption that plating or soldering or welding or crimping would prevent that process from occuring????

""These questions of yours, on my measurements, are about as likely.
Of course, I looked up any evidence of thermoelectric effects, but I did not find any that applied.""JC

Hmmmm..review what I have just posted, think about it, ask questions, or look it up...Rather than your glib remarks discounting it.

""For the record, I used thermocouples in measurement of temperature virtually every hour of every working day for almost year,""JC

For the record, so does my toaster oven..and it also demonstrates the same understanding of how they work..

""I have some idea of how they work, the dissimiliar materials used and the fact that it is a continuous offset, not a sporadic one. How is this going to generate harmonic distortion about 5KHz, when I have an 18/oct 400 Hz filter installed? ""JC

Hmmm..since dissimilar metals generate a non linear, temperature sensitive junction at some level, how can you ask that question??

""This unfounded criticism of yours is typical of why many audio designers distrust 'referees' associated with the AES. But that is another story. ""JC

If you go back and review every single solitary post I have put up regarding this effect, you would see that the only criticism I have stated is regarding your stupidity w/r to attitude and people skills.

You know, it is not necessary to post really stupid statements to get me to explain something..All you really have to do is ask..I'm more than happy to educate you in regard to things you don't know. As well as placing in public domain what I believe to be accurate so that my understanding can also be questioned. After all, we're all human and make mistakes..

Review everything I've said John.. I've not stated that the seebeck/peltier effect is causing what you are measuring..I initially asked you if you thought that it was a possible mechanism. To that, you glibly replied "bull shit".

If you are personally laughed at, discounted, ignored, by AES and other professional people, it is because of your own "people skills". Not because of their own ignorance..It's not the rest of the world, John....You make it clear it's you..

Cheers, John



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